1. Field of the Invention
Embodiments of the present invention generally relate to a current feedback digital charge accumulator for an input device.
2. Description of the Related Art
Input devices including proximity sensor devices (also commonly called touchpads or touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which the proximity sensor device determines the presence, location, and/or motion of one or more input objects. Proximity sensor devices may be used to provide interfaces for the electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems, such as touchpads integrated in, or peripheral to, notebook or desktop computers. Proximity sensor devices are also often used in smaller computing systems, such as touch screens integrated in cellular phones or tablet computers.
Proximity sensor devices may include one or more types of electrodes configured for transmitting and/or receiving input sensing signals. When performing input sensing, signals are typically first acquired in the analog domain. Various types of processing may then be performed with the analog signals prior to converting the signals into the digital domain. However, processing input sensing signals using analog circuitry generally requires larger components, such as large capacitors and/or resistors. In addition, as the feature size of proximity sensor devices is decreased, the size of the analog circuitry generally must be increased.
Accordingly, there is a need for reducing the number of analog components needed to perform input sensing in proximity sensor devices.